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Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust

Latest news

Recent projects

  • Latest news

    27 Aug 2026

    LiDAR, UAV and GIS used for Slope Stability Assessment

    Geoff Davis has recently been working on another coastal caravan site with slope stability problems.On this site, Lewis Brown Chartered Land Surveyors used remote sensing (LiDAR (Light Detection and Ranging)) from a UAV (unmanned aerial vehicle) to help understand the locations and magnitude of ground movements.Ruddlesden geotechnical then used GIS (Geographic Information System)  to highlight areas of concern, to quantify the degree of movement, which might have otherwise been missed.These technologies have been great in helping us understand the landslide processes at this site and, equally importantly, convey to others what is happening. However, they are of little use without a detailed understanding of the geological and geomorphological processes, which inform the all-important ground model, i.e. they should be seen as a useful tool to help us understand and communicate landslide processes, rather than a replacement for the understanding of them.

    LiDAR, UAV and GIS used for Slope Stability Assessment
    LiDAR, UAV and GIS used for Slope Stability Assessment

  • Recent projects

    Iron and Manganese Testing undertaken Instead of Remediation

    An effervescent (oily) and rusty sheen was noted on water within initial foundation excavations and concern was raised about possible contamination from a nearby former railway siding. A walkover survey and geological knowledge identified the effervescent and rusty sheen as being of natural origin. Some bacteria (leptothrix discophora) that live in waterlogged places get their energy from iron and manganese, and, as these harmless bacteria grow and decompose, the iron may appear oily or form red or orange films, fluffs and coatings. It was also noted that a mining report stated that mines in the area were mainly mined for manganese, i.e. the underlying geology is rich in manganese. Therefore, no remedial measures were required. This was confirmed by UKAS accredited contamination laboratory testing.

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  • Recent projects

    Bioaccessibility Testing Negates Remediation

    The chemical laboratory test results obtained as part of a Phase 2 contamination investigation for a proposed residential development in South Devon indicated elevated levels of arsenic to be present in natural soils. A generic qualitative risk assessment (GQRA) showed that all the recorded levels of arsenic exceeded the generic assessment criteria (GAC), indicating that remediation or further assessment was required. Based on the conceptual site model (CSM), as no significantly elevated levels of contamination were expected, but given the underlying geology naturally elevated levels of metals and metalloids may be present, it was considered that further assessment should be undertaken instead of remediation. A detailed quantitative risk assessment (DQRA) was therefore carried out, including additional bioaccessibilitytesting, as the GAC to which the recorded levels of arsenic were initially compared assumes that 100% of the arsenic is bioaccessible, whereas naturally occurring elements are typically not 100% bioaccessible. The bioaccessibility test is a laboratory test that simulates conditions in the gastrointestinal tract to assess the human bioaccessibility of potentially harmful elements by ingestion. As the ingestion pathway is the primary migration pathway for arsenic, the bioaccessibility significantly affects the assessment criteria. The results of the bioaccessibility testing were incorporated into the CLEA, in which the end users were also modified, as the proposed development was for a residential care home rather than a standard residential land use, to produce a site-specific assessment criterion, which was greater than all of the recorded levels of arsenic. It was therefore concluded that the recorded levels of arsenic were not likely to be harmful to end users, given the proposed end use, and that no remediation was necessary. Carrying out this further testing and detailed quantitative risk assessment (DQRA) avoided the need to carry out unnecessary remediation.

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